Westlake Girls is the latest education provider taking steps to counteract the spread of swine flu. Photo / Herald file

Westlake Girls is the latest education provider taking steps to counteract the spread of swine flu. Photo / Herald file

All year 12 students at Auckland's Westlake Girls High School have been told to stay home from school for a week following a spread of confirmed cases of swine flu.

The number of swine flu cases has risen from 43 to 71 in the last 24 hours, but Health Minister Tony Ryall says there is no reason for alarm, and that more cases are to be expected.

"We are working to contain the spread as much as possible. This is a rapidly changing situation with cases increasing exponentially both here and many states in Australia."

Included are the first cases confirmed in the Bay of Plenty and Lakes District Health Board region; a 15-month-old American boy holidaying with his family and a Tauranga teenager.

Both went to medical centres while displaying symptoms, the Tauranga teen to her GP and the toddler to the Taupo Hospital emergency department (ED).

Medical Officer of Health Phil Shoemack said the boy's family had been in New Zealand for five days when he became ill.

"The family was tracked down at a relative's place in Wellington, and the public health follow-up work is being carried out by Hutt Valley staff," he said.

"The American family and relatives the family is staying with has been asked to stay put in the household and await further instructions from the public health staff."

The teenager's flatmates, colleagues and other close contacts were being contacted.

Dr Shoemack said he was not sure if the teenager or the toddler's family had phoned before visiting the GP and ED respectively but reiterated the need for people to do so.

"If you suspect you or your family member has influenza ... we'd prefer that you didn't go to an ED of a hospital," he told NZPA.

"What we're trying to do is get people, as much as possible, to get in contact by telephone first, so that they can get appropriate instructions."

People would either be told what action to take at home or, if a visit was deemed necessary, a specific time would be made and they would be directed to a certain door rather than having them in the waiting room.

"Emergency departments are always busy, especially through winter, and we're not wanting people with infectious disease to turn up unannounced, because it just heightens the likelihood that they might pass their bugs on, whatever it is they've got."